Exemplary embodiments of the present application relate to brake pads for motor vehicle brake systems, and more specifically to backing plates for brake pads.
Generally, in motor vehicle wheel brakes, braking friction is caused by a set of brake pads that press against the inner surface of the surface of a rotating disc or drum that is connected to a rotating wheel of a vehicle. Thus, brake pads play an important role in the braking systems for all types of automobiles or vehicles equipped with disc or drum brakes. Brake pads, mounted in a brake caliper assembly and located at the wheels, typically comprise a backing plate having a friction material disposed thereon wherein the friction material makes contact with the rotating surface of the wheel (that is, a rotor or a drum).
As a vehicle travels, the rotor or drum rotates with the wheels of the vehicle. The brake caliper assemblies, having brake pistons, are rigidly mounted to a non-rotating component of the vehicle, such as the vehicle's frame. Upon application of the brake pedal, hydraulic fluid drives the brake pistons outward from cylinders in the caliper assemblies, thereby forcing the brake pads to engage the rotating braking surface. The vehicle is resultantly slowed as the frictional braking forces created between the brake pads and the braking surface oppose the rotation of the wheel and convert the vehicle's kinetic energy to heat.
During braking, however, the braking surface excites the brake pads, causing the brakes to vibrate and transmitting some of the vehicle's kinetic energy into sound and vibration, which are undesirable byproducts. The brake pads can also be excited by other stimuli, such as the vehicle drive train components that transmit energy to the brake pads that causes them to vibrate. By transmitting the vibrations through the surrounding air or through the structure of the vehicle, vibrating braking plates can generate noise that is audible to vehicle occupants. This noise can take the form of a particularly annoying squeal otherwise known as “brake squeal”.
The brake pads may also excite other components, causing them to vibrate and thereby emit undesirable noise. When the squealing phenomenon arises, not only do vibrations of the braking surface and of the brake pad occur, the various components of the brake vibrate in resonance, influencing one another. In other words, a chain of vibrating elements is established, starting from the disk and passing through the pads and the caliper body until it also involves the suspension of the vehicle and the vehicle body itself. Each element making up the brake assembly vibrates at its own natural frequency.
Accordingly, it is desirable to provide a backing plate for a brake pad that diminishes the adverse effects of the vibrational forces passing by the brake pad.